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MP3214
500mA LED Camera Flash
Charge Pump
The Future of Analog IC Technology
DESCRIPTION
FEATURES
The MP3214 is a low noise, high current charge
pump designed to drive LEDs at up to 500mA
with an input supply of 2.7 to 5.5 volts. The high
efficiency and low external parts count (two
small bypass caps, two small charge pump
caps, and one programming resistor) make the
MP3214 ideally suited for portable applications
where small size and high efficiency are critical.
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The MP3214 controls the inrush current via a
soft start algorithm. High frequency switching of
the charge pump capacitors allows for very
small capacitance values.
The output current is set by an external resistor,
RSET. The brightness of the LED can be
modulated by a PWM on the enable pin.
The MP3214 automatically adjusts the
switching mode of the charge pump for optimal
efficiency.
The MP3214 is available in a 16 pin 3x3mm
QFN package.
High Efficiency
Up to 500mA Output Current
Wide Supply Range of 2.7V to 5.5 V
Small Solution Size
Soft Start
Low Shutdown Current
Open/Short Led Protection
No Inductors
Programmable Output Current
PWM Brightness Control
APPLICATIONS
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LED Backlight
LED Flash
LED Torch/Flashlight
Cell Phones, Cameras, PDA, and Handheld
Equipment
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“MPS” and “The Future of Analog IC Technology” are Registered Trademarks of
Monolithic Power Systems, Inc.
TYPICAL APPLICATION
MP3214 Rev. 1.01
6/24/2011
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
1
MP3214 – 500mA LED CAMERA FLASH CHARGE PUMP
ORDERING INFORMATION
Part Number*
MP3214DQ
Package
QFN16 (3 x 3mm)
Top Marking
Free Air Temperature (TA)
2F
-40°C to +85°C
* For Tape & Reel, add suffix –Z (g. MP3214DQ–Z).
For RoHS compliant packaging, add suffix –LF (e.g. MP3214DQ–LF–Z)
PACKAGE REFERENCE
TOP VIEW
PIN 1 ID
NC
16
IOUT IOUT
15
14
NC
13
CP
1
12
NC
C2B
2
11
ISET
C1B
3
10
TOE
C1A
4
9
GND
5
6
7
8
GND
C2A
VIN
EN
EXPOSED PAD
CONNECT TO PIN 5, 9
ABSOLUTE MAXIMUM RATINGS (1)
Thermal Resistance
All Other Pins ...............................-0.3V to +6.5V
(2)
Continuous Power Dissipation (TA = +25°C)
………………………………………………....2.1W
Junction Temperature ...............................150°C
Lead Temperature ....................................260°C
Storage Temperature............... -65°C to +150°C
Supply Voltage VIN............................2.5V to 6V
QFN16 (3 x 3mm) ...................60 ...... 12 ... °C/W
Recommended Operating Conditions
(2)
Supply Voltage VIN ..........................2.7V to 5.5V
Maximum Junction Temp. (TJ) ................+125°C
MP3214 Rev. 1.01
6/24/2011
(3)
θJA
θJC
Notes:
1) Exceeding these ratings may damage the device.
2) The maximum allowable power dissipation is a function of the
maximum junction temperature TJ (MAX), the junction-toambient thermal resistance θJA, and the ambient temperature
TA. The maximum allowable continuous power dissipation at
any ambient temperature is calculated by PD (MAX) = (TJ
(MAX)-TA)/θJA. Exceeding the maximum allowable power
dissipation will cause excessive die temperature, and the
regulator will go into thermal shutdown. Internal thermal
shutdown circuitry protects the device from permanent
damage.
3) The device is not guaranteed to function outside of its
operating conditions.
4) Measured on JESD51-7, 4-layer PCB.
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MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
2
MP3214 – 500mA LED CAMERA FLASH CHARGE PUMP
ELECTRICAL CHARACTERISTICS
VBATT = 3.6V, C1=C2=2.2μF, COUT=4.7μF, CBYPASS=1μF, TA = +25°C, unless otherwise noted.
Parameter
Input Supply Voltage
Supply Current
Shutdown Current
ILED Drop Out Voltage
LED Current Turn On Delay
Clock Frequency
En Threshold High
En Threshold Low
IOUT Gain Accuracy
Gain Coefficient
Thermal Shutdown
Symbol
VIN
IIN
ISHUTDOWN
Condition
IOUT Measured with RSET=17.8k
IOUT =Gain/RSET
Min
2.7
186
-8%
Typ
3
0.1
0.3
4
1.35
0.81
0.75
202
3600
150
Max
5.5
218
+8%
Units
V
mA
µA
V
µs
MHz
V
V
mA
V
°C
Note:
5) Current matching definition: (Max – Min)/(Max + Min)
6) Guaranteed by design.
MP3214 Rev. 1.01
6/24/2011
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
3
MP3214 – 500mA LED CAMERA FLASH CHARGE PUMP
PIN FUNCTIONS
Pin #
Name Description
1
CP
2
C2B
3
C1B
4
C1A
5,9
Charge pump bypass for common anode version. Connect a 2.2µF bypass capacitor to GND.
GND Battery Power Ground. Connect the exposed pad to this pin.
6
C2A
7
VIN
8
EN
10
TOE
11
ISET
12,13,16
NC
14,15
Charge Pump Capacitor #2 Negative Node. Connect the negative side of the #2 charge pump
capacitor to C2B.
Charge Pump Capacitor #1 Negative Node. Connect the negative side of the #1 charge pump
capacitor to C1B.
Charge Pump Capacitor #1 Positive Node. Connect the positive side of the #1 charge pump
capacitor to C1A. Typical applications require C1 to be 1µF.
Charge Pump Capacitor #2 Positive Node. Connect the positive side of the #2 charge pump
capacitor to C2A. Typical applications require C2 to be 1µF.
Battery Power Input. Connect the 2.5V to 5.5V input source between BATT and GND. Bypass
BATT to GND with a 2.2µF or greater capacitor.
Enable input.
Time Out Enable. With TOE=1 the time out is enabled. The device will keep operating for a
period of time after the EN pin goes low.
Current Control Input. Connect a resistor between ISET and GND to set the LED current up
to 500mA.
No connection.
Driver for Flashlight. Connect the flashlight LED between this pin and BATT, with the anode
IOUT at BATT.
BLOCK DIAGRAM
Figure 1—Functional Block Diagram
MP3214 Rev. 1.01
6/24/2011
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
4
MP3214 – 500mA LED CAMERA FLASH CHARGE PUMP
TYPICAL PERFORMANCE CHARACTERISTICS
Flash Current Regulation vs.
Battery Voltage:
100
IFlash=100mA
IFlash=200mA
EFFICIENCY(%)
90
IFlash=300mA
IFlash=500mA
80
70
60
50
40
30
2.0
4.0
5.0
3.0
V_BATTERY(V)
FLASH CURRENT VARIATION(%)
Efficiency
6.0
0.0
-0.05
-0.10
-0.15
-0.20
-0.25
2.5 2.9 3.3 3.7 4.1 4.5 4.9 5.3 5.7
V_BATTERY(V)
230
210
190
170
150
130
110
90
70
50
V_Battery=2.7V
30
V_Battery=3.5V
10
10 20 30 40 50 60 70 80 90 100
DUTY CYCLE(%)
MP3214 Rev. 1.01
6/24/2011
Measurement
550
500
450
I_FLASH(MA)
AVERAGE FLASH CURRENT(MA)
Average Flash Current vs.
Dimming Duty Cycle
400
350
300
250
200
150
100
0.02
0.04 0.06 0.08
0.1 0.12 0.14
1/RSET(1/KOHM)
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
5
MP3214 – 500mA LED CAMERA FLASH CHARGE PUMP
TYPICAL PERFORMANCE CHARACTERISTICS
Charge Pump
Charge Pump
Start up and Shut down
Vin=3.5V, I_LED =500mA, 1.5X mode
Vin=2.7V, I_LED =500mA, 2.0X mode
Start up at 1X Mode, V_BAT=4.2V
V_C1A
2V/div
V_C1B
2V/div
V_C2A
2V/div
V_C2B
2V/div
V_C1A
2V/div
EN
2V/div
V_C1B
2V/div
V_CP
1V/div
V_C2A
2V/div
V_C2B
2V/div
I_Flash
200mA/div
Start up and Shut down
Start up and Shut down
Start up and Shut down
Shut down at 1X Mode, V_BAT=4.2V
Start up at 1.5X Mode, V_BAT=3.5V
Shut down at 1.5X Mode, V_BAT=3.5V
EN
2V/div
EN
2V/div
EN
2V/div
V_CP
1V/div
V_CP
1V/div
V_CP
1V/div
I_Flash
200mA/div
I_Flash
200mA/div
I_Flash
200mA/div
Start up and Shut down
Start up and Shut down
Start up at 2X Mode, V_BAT=2.7V
Shut down at 2X Mode, V_BAT=2.7V
EN
2V/div
EN
2V/div
V_CP
1V/div
V_CP
1V/div
Mode 1.5X to 1X retry
V_CP
1V/div
V_C1A
2V/div
I_BAT
500mA/div
I_Flash
200mA/div
MP3214 Rev. 1.01
6/24/2011
I_Flash
200mA/div
V_C1B
2V/div
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
6
MP3214 – 500mA LED CAMERA FLASH CHARGE PUMP
TYPICAL PERFORMANCE CHARACTERISTICS
Mode change from 1X to 1.5
V_CP
2V/div
V_CP
2V/div
V_C1A
2V/div
V_C1A
2V/div
I_BAT
500mA/div
I_BAT
500mA/div
V_C1B
2V/div
V_C1B
2V/div
MP3214 Rev. 1.01
6/24/2011
Mode change from 1.5X to 2X
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
7
MP3214 – 500mA LED CAMERA FLASH CHARGE PUMP
OPERATION
Using the Enable Pin to PWM the LED
Current
The Enable (En) pin can enable (logic 1) or
disable (logic 0) the part. When disabled, the
part enters a low current sleep mode.
There is an internal one shot on the enable pin.
The enable pin must go low for more than
30mS in order to completely disable the part
and enter the low current shutdown mode.
Although the part internally does not
immediately shut off, the output drive to the
LED does immediately turn off.
A low frequency PWM on the enable pin (50Hz
to 2kHz) can be used to change the LED
brightness. For example, if a 20% duty cycle
PWM signal is applied to the enable pin, the
average output current is 20% the full current.
Setting the Output Current
The output current is set by the resistor RSET.
RSET is connected from the ISET pin to ground.
The output current follows the equation:
IOUT =
3570
RSET
or for a desired IOUT, RSET is calculated by:
RSET =
3570
IOUT
For example:
RSET
7140Ω
8925Ω
11900Ω
17850Ω
35700Ω
MP3214 Rev. 1.01
6/24/2011
IOUT
500mA
400mA
300mA
200mA
100mA
Charge Pump Operation
Normal battery operation will supply a voltage
that is initially high (roughly 4.2volts when fully
charge) falling to a mid voltage for much of it’s
life ( roughly 3 to 3.6 volts) and finally dropping
to a low voltage (roughly 2.7 to 3.0 volts) when
fully discharged. At the high end of the battery
voltage, the LED can be driven directly from the
battery to ground. As the battery discharges,
the voltage must be boosted to allow enough
forward voltage to turn on the LED. On the
MP3214, the boost voltage pushes the charge
pump output (CP) below ground to gain the
required headroom.
The charge pump gain can be changed on the
fly to optimize the charge pump voltage for
maximum efficiency.
The gain can be
configured to be 1, 1.5 or 2. The charge pump
gain control is accomplished automatically by
an internal feedback network.
Time Out Enable
The TOE function acts to extend the device
operation, for a period of time, after the enabled
pin goes low. With TOE=1 the time out is
enabled. When the enable pin goes high, the
part turns on as in normal operation. When the
enable pin goes low, the part and the output,
remain on for an extra 1.55 seconds.
When TOE=0, the enabled pin functions directly
bases on the logic level of the input. The part
turns on when enable is high, and off when
enable is low.
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
8
MP3214 – 500mA LED CAMERA FLASH CHARGE PUMP
PACKAGE INFORMATION
QFN16 (3 x 3mm)
2.90
3.10
1.50
1.80
0.30
0.50
PIN 1 ID
MARKING
0.18
0.30
2.90
3.10
PIN 1 ID
INDEX AREA
13
16
12
PIN 1 ID
SEE DETAIL A
1
1.50
1.80
0.50
BSC
4
9
5
8
TOP VIEW
BOTTOM VIEW
PIN 1 ID OPTION A
0.30x45” TYP.
PIN 1 ID OPTION B
R0.20 TYP.
0.80
1.00
0.20 REF
0.00
0.05
DETAIL A
SIDE VIEW
2.90
NOTE:
1.70
1) ALL DIMENSIONS ARE IN MILLIMETERS.
2) EXPOSED PADDLE SIZE DOES NOT INCLUDE MOLD FLASH.
3) LEAD COPLANARITY SHALL BE 0.10 MILLIMETER MAX.
4) DRAWING CONFORMS TO JEDEC MO-220, VARIATION VEED-4.
5) DRAWING IS NOT TO SCALE.
0.70
0.25
0.50
RECOMMENDED LAND PATTERN
NOTICE: The information in this document is subject to change without notice. Users should warrant and guarantee that third
party Intellectual Property rights are not infringed upon when integrating MPS products into any application. MPS will not
assume any legal responsibility for any said applications.
MP3214 Rev. 1.01
6/24/2011
www.MonolithicPower.com
MPS Proprietary Information. Patent Protected. Unauthorized Photocopy and Duplication Prohibited.
© 2011 MPS. All Rights Reserved.
9